Antiperspirants and deodorants generally available are in the form of aerosol suspensions, roll-on powders, emulsions and solids.
Clear antiperspirants have been attempted, but to date, none has reached the market place. It is believed that a clear antiperspirant product which offers efficacy and aesthetic properties equal to or better than products presently available would be well received by the purchasing public.
Clear stick deodorant compositions have been available for some time. The clear sticks are generally produced by using stearate soaps as gelling agents for an alcoholic or gylcolic solution of an anti-microbial agent and a fragrance. These deodorant products offer no antiperspirant protection. The use of antiperspirant active ingredients, which are cationic in nature, in the aforesaid deodorant compositions, is chemically incompatible due to the chemical interaction/inactivation between the antiperspirant active material and the soap.
Products of gel consistency can be achieved through the use of gelling agents such as cellulosic or algin derived polymeric materials. Synthetic resins can also be utilized. These materials however are incompatible with electrolites (antiperspirants salts) especially at the levels required for antiperspirant efficacy and at the low pH regime of these preparations. "Gelling agents" work on the concept that when these polymeric materials dissolve or swell in water or other mediums at a sufficient high concentration form gel like products. These are not emulsions. The gel is formed when the gellant crystals are forced out of solution in very fine particle size. These crystals interlock in quiescent state to give the gel its body.
Some cellulosic materials, such as hydroxypropylcellulose, among others, are compatible with polyvalent metal salts and have been used in the manufacture of clear lotions. These cellulosic materials, however, must be prepared with a high percentage of water or alcohol in order to insure solubilization of the active ingredient. Such formulations, in addition to a high irritation potential, are tacky and pituitous and low in efficacy when alcohol based, and exhibit tackiness and long drying time when water based.
A second way of preparing gel type product involves the use of hydrophilic surfactants at sufficiently high levels in aqueous solutions. These products, prepared with conventional surfactants will solubilize oils. Normally they are slow drying and not too aesthetic. In addition, due to the high level of non volatiles, these are also expected to have low antiperspirant efficacy.
We have developed a clear microcrystalline emulsion of gel consistency without the use of gelling agents nor conventional emulsifiers/surfactants. We were able to do so with low levels of unique silicone emulsifiers. Furthermore the microcrystalline emulsion is aesthetically pleasing, fast drying and is an effective antiperspirant.
Wax and soap-gel and gelled antiperspirant sticks are disclosed in various United States patents i.e. U.S. Pat. Nos. 4,382,079; 4,414,200; 4,280,994; 4,265,878, 3,259,545; 2,970,083; 2,933,433; 2,900,306; 2,857,315 and 4,383,988.
Gelled antiperspirants have been disclosed in U.S. Pat. No. 4,383,988.